Operating mechanism for printing presses and the like



Aug. 1, 1950 J. SINKQVITZ OPERATING MECHANISM FOR PRINTING PRESSES ANDTHE LIKE 6 Sheets-Sheet 1 Filed Feb. 1, 1946 IN V ENTO R dosepfzf/hAow'fz z LM w m mkmmwm kkk Aug. 1, 1950 J. SINKOVITZ OPERATING MECHANISMFOR PRINTING PRESSES AND THE LIKE 6 Sheets-Sheet 2 Filed Feb. 1, 1946 Wm m M N Aug. 1, 1950 J. SINKOVITZ OPERATING MECHANISM FOR PRINTINGPRESSES AND THE LIKE 6 Sheets-Sheet 5 Filed Feb. 1, 1946 g- 1950 J..SlNKOVlTZ 2,

OPERATING MECHANISM FOR PRINTING PRESSES AND THE LIKE Filed Feb. 1, 19466 Sheets-Sheet 4 INVENTOR 1, 1950 v J. SINKOVITZ 7,

OPERATING MECHANISM FOR PRINTING PRESSES AND THE LIKE Filed Feb. 1, 19466 Sheets-Sheet 5 ;\I 64 W I I r n a n fi n n r n r l N v E N TO R dose0h Jmkowfz Aug. 1, 1950 J. SINKOVITZ 17,

OPERATING MECHANISM FOR PRINTING PRESSES AND THE LIKE Filed Feb. 1, 19466 Sheets-Sheet 6 INVENTOR 2% I 27 74 Joseph f/nA ou/fz fatented Aug. 1195 OPERATING MECHANISM FOR PRINTING PRESSES AND THE LIKE JosephSinkovitz, Pittsburgh, Pa., assignor to Miller Printing Machinery 00.,Pittsburgh, Pa., a corporation of Pennsylvania I Application February 1,1946, Serial No. 644,918

8 Claims. f 1

This invention relates to operating mechanism for printing presses andthe like. It relates particularly to operating mechanism for a printingpress or the like having anoscillating element such as a bed. Theinvention provides means for driving the oscillating element; when it isemployed for driving the bed of a printing press I each end of thestrokegalso the bed driving mechanism has had a tendency to skew thebed. Both of these factors are greatly, magnified in,

presses operated at high speed and impose upon he Working s rvh li tresih y a tend toward imperfection in printing unless counteracted byadditionalandjerpensive means.

As a result it has been" necessary to provide especially strong andmassive driving, operating and supporting mechanism to insure properoperation of the pressat the desired speed despite the great mass ofmoving parts 'andto effectively counteract the tendency of the bedtoskew. in turn has undesirablyincreased the cost and size of presses aswell as the expense of operation due to power merit parts.

l I provide a simple and efiicient' bed motion well consumption j andcost of j replaceadapted for high speed operation in which the mass ofthe bed and associated mechanism is greatly reduced and the beddrivingmechanism acts on the bed in such away as toavoid any substantialtendency toward skewing. I eliminate entirely the use of bedhangersandprovidebed driving means of comparatively-very light weight, greatlyreducing the dead Weight-of-the bed and making possible high speedoperation employing a minimum of power. I may use a substantiallysmaller motorthan would otherwisebe necessary,

and in general the press may be more lightly olesigned, resulting inansimportantrsaving' in first cost and cost of upkeep and o aeration.

I preferably provide "separate means for driv-.

ing the bed during constant speed motion and for reversing the bed atthe ends of its stroke.

I provide for drivingslthe bed duringconstant speed motion by applyingthewdrivingforceto 2 the bed in such a way as to avoid any substantialtendency to skew the bed. Desirably I provide an elongated operatingmember adapted to be carried by the bed to lie generally in alongitudinal plane perpendicular thereto and containing the center ofgravity thereof and means coacting with said member to drive the bed inboth directions of oscillation. The elongated operated member mayconvenientlytake the form of a rack, and the means coacting therewithmay conveniently take the form of pinion means. For example, I mayemploy two pinions rotating in opposite directions, and bring suchpinions alternately into mesh with the rack to drive the bed duringconstant speed motion. The pinions may be geared together in such mannerthat when one of them turns in either direction the other turns in theopposite direction. Means may be provided for shifting the pinionstransversely of the rack to bring first one and then the other into meshwith the rack.

Desirably the pinions for driving the bed during constant speed motionare out of mesh with the rack at the ends of the stroke of the bed whenit is being reversed. This may be accomplished by providing the rack ofsuch length that its trailing end passes out of mesh with the pinionwhich has been driving it during constant speed motion of the bed beforeor at approximately the instant when the bed beginsto slow down forreversal.

As above indicated reversing of the bed is desirably accomplished bymeans separate from the means above referred tofor driving the bedduring constant speed motion. I preferably provide an elongatedoperating member adapted to be carried by the bed and means coactingwith such elongated operating member for slowing down, stopping andreversing the bed at at least one end of its oscillatory movement. Theelongated operated member may conveniently take the form of a rack andthe means coacting there with may take the form of a pinion meshingtherewith after the rack through which the bed is driven in constantspeed motion has passed beyond the driving pinions coacting therewith. Ifind it desirable to render operative the bed reversing means atapproximately the same time" as the means for driving the bed inconstant speed motion are rendered inoperative. The two 3 1 preferablyemploy similar bed reversing mechanisms for reversing the bed at therespective ends of its stroke.

Reversal of the bed is preferably accomplished by oscillatory meansmoving at first in synchronism with the bed at the end of its constantspeed motion,, the oscillatory means being slowed to a stop and thenmoved back in the opposite direction to reverse the bed. The oscillatorymeans may take the form of a crosshead operated by a crank, thecrosshead carrying a rack meshing with a gear or segment which in turnis connect ed, directly or through intermediate gearing, with the pinionmeshing with the rack on the bed which is used for bed reversal. I findit convenient to employ a single oscillatory member consisting of acrosshead operated by a crank, the crosshead carrying two racksrespectively connected through gearing to act on the pinions which meshwith the racks connected with the bed for effecting reversal of the bedat the respective ends of its stroke. 7 A Other details, objects andadvantages of the invention will become apparent as the followingdescription of a present preferred embodiment thereof proceeds. V

In the accompanying drawings I have shown a preferred embodiment of theinvention, in which Figure 1 is a vertical transverse cross-sectionalview through a portion of a printing press show ing the bed motion; m

Figure 2 is a plan view ofthe bed motion; and

Figures 3 to 10, inclusive, are diagrams showing the positions ofcertain of the parts at various stages during the press cycle, asfollows:

Figure 3 shows the bed at the end of its cons'tant speed motion toward.the left on the return or non-printing stroke, the bed being ready toslow down;

. Figure 4 shows the bed stopped at the end of the return stroke readyto move toward the right on the impression or printing stroke;

Figure 5 shows the bed moving toward the right on the impression strokeand at the beginning of constant speed motion;

Figure 6 shows the bed in the middle of constant speed motion movingtoward the righton the impression stroke; A

Figure 7 shows the bed at the end of its constant speed motion towardthe right on the impression stroke and ready to slow down;

Figure 8 shows the bed in its extreme right hand position at the end ofthe impression stroke and ready to move back toward the left on thereturn stroke; I

Figure 9 shows the bed at the beginnin of constant speed motion, on thereturn stroke;

Figure 1c shows the bed in the middle'of constant speed motion on thereturn stroke.

Referring now more particularly to the draw ings, there is shown at 2the impression cylinder of a fiat bed and cylinder press and at 3the'bed of the press. The press may operate in conventional manner, thecylinder rotating continuously in the same direction (counterclockwisein Figures 3-10) and making two complete revolutions for each cycle ofthe bed; that is, the cylinder rotates once while the bed is movingforward on the impression or printing stroke and once while it is movingback on the return stroke. When the bed moves forward on the impressionstroke the cylinder cooperates with the bed in printing. On the returnstroke of the bed the cylinder while continuously rotating in theforward direction is raised relatively to the bed so that it does notcontact the bed, as shown, for example, in Figures 9 and 10. This is thestandard method of operation of flat bed and cylinder presses and themechanism for raising and lowering the impression cylinder duringoperation is well known.

Connected with the cylinder 2 coaxially therewith and having a pitchdiameter equal to the diameter of the cylinder is a cylinder drivinggear 4. The cylinder driving gear 4 meshes with an idler pinion 5rotatably carried on a stub shaft 6 mounted in the press frame I. Journaled for rotation in the press frame is a shaft 8 to which is keyeda gear 9 meshing with the pinion 5. Also keyed to the shaft 8 is a gearID.

Journaled for rotation in the press frame is a shaft H to which is keyeda flywheel l2. Also keyed to the shaft is a pulley I3. The press isdriven by an electric motor (not shown) which drives a pulley M. Aseries of V belts |5 are trained about the pulley l3 and I4. Thus whenthe motor is operated it rotates the pulley l4 which through the beltsl5 causes rotation of the pulley is. This turns the flywheel shaft H.

Keyed to. the flywheel shaft II is a pinion I6 which meshes with thegear I!) keyed to the shaft 8. Thus the motor through the shaft drivesthe shaft 8 continuously in the same direction; and the shaft 8 throughthe gear 9, the pinion 5 and the gear 4 rotates the impression cylinder2 continuously in the same direction.

Mounted in the press frame for rotation and also for axial movement is ashaft Pinned to the shaft I! are two spaced apart collars H3. Mounted onthe frame is a bracket I!) to which is pivoted at 20 a lever 2| whoseupper end is bifurcated and carries opposed rollers 22 positionedbetween the collars l8 and of such diameter as to simultaneously engagesaid collars, as shown in Figures 1 and 2. The lower end of the lever 2|carries a cam follower roller 23 which operates in a cam groove 24 of arotary cam 25 keyed to a shaft 26 rotatably mounted in the press frame.Also keyed to the shaft 26 is a gear 2''! which meshes with a pinion 2Bpinned to the shaft 8. Thus upon rotation of the shaft 8 the cam 25 iscaused to rotate continuously, and that cam through the cam groove 24and the cam follower roller 23 causes the lever 2| to oscillate aboutthe axis of its pivotal connection 20 with the bracket |9. But as'therollers 22 carried by the lever 2| are positioned between and in contactwith the collars H! which are pinned to the shaft I! the angularoscillation of the lever 2| causes axial oscillation of the shaft IT.The cam groove 24 is designed to oscillate the shaft I! from one extremeposition to the other when the bed iS adjacent each end of its stroke,that is, after conclusion of the constantspeed motion of the bed in eachdirection. During the constant speed motion of the bed the cam followerroller 23 dwells in a circular portion of the cam groove 24 to hold theshaft |8 in one or the other of its extreme axial positions. The reasonfor axial shifting of the shaft I! will presently'appear.

Mounted on the shaft I1 is a pinion 29 which is always in mesh with thegear ln'regardless of the axial'position of the shaft H. To insure thatthe pinion 29 will-always remain in mesh with the gear ID the former ismade with a wide face as shown in Figures 1 and 2. I prefer to pin thepinion 29 to the-shaft H as shown at 30 in Figure 1 so as to cause theshaft I! to rotate during operation of the press. While it is notnecessary that the shaft I! rotate this is desirable because of itsendwise movement. If the shaft is turning it will move endwise in itsbearings much more freely than if it were non-rotative.

Positioned on the shaft ll adjacent the pinion 29 is a pinion 3| whichis of the same diameter as the pinion 29. The pinion 3| is designed torotate relatively to the shaft l1, wherefore a bushing 32 is interposedbetween the pinion 3| and the shaft. A collar 33 is pinned to the shaftl1 and maintains the pinion 3| and the bushing 32 in place on the shaftI! in fixed axial position relatively to the pinion 29. Between thepinions 29 and 3| is a frame or spider 34 (Figures 1, 2 and :3) havingthree radial shafts 35 equally spaced angularly about the frame orspider with a bevel pinion 36 mounted on each shaft 35. Fastened to thepinion 29 by screws 31 is a bevel gear 38.

Fastened to the pinion 3| by screws 39 is a bevel gear 49 of the samesize as the bevel gear 38. The

bevel gears 38 and 49 mesh with the bevel pinions 36 of the spider 34.

The spider 34 has a projection 4| extending out between the pinions 29and 3| which projection has its end bifurcated as shown at 42 in Figure3 to embrace a rod 44 mounted in the press frame. This prevents thespider from turning about the axis of the shaft l I. The spider islikewise maintained in fixed position axially of the shaft ll so that itpartakes of the axial movements of that shaft along with the pinions 29and 3|. When the shaft |'l moves axially the. bifurcated end 42 of theprojection 4| slides along the rod 44.

Since the spider 34 is held against turning, and since the bevel pinions36 mesh with the bevel gear 38 carried by the pinion 29 and also withthe bevel gear carried by the pinion 3|, the pinions 29 and 3| willalways be caused, when one of them is driven, to rotate in oppositedirections at the same speed. The pinion 29, being pinned to the shaftll, has no movement relatively to the shaft, but the pinion 3| rotatesin the direction opposite the direction of rotation of the shaft, therelative rotational speed of the pinion 3| and the shaft being doublethe rotational speed of the shaft.

Fastened to the under face of the bed 3 is an elongated operating memberin the form of a downwardly facing rack 45. The rack 45 extends parallelto the length of the bed and parallel to the direction of oscillation ofthe bed. It is preferably disposed to lie generally in a longitudinalplane perpendicular to the bed and containing the center of gravitythereof. If the bed is transversely symmetrical the rack 45 ispreferably disposed at the longitudinal center line thereof. The reasonfor thus disposing the rack 45 is to avoid any substantial tendencytoward skewing of the bed when it is driven during constant speedmotion, especially on the impression stroke. The rack 45 is adapted tomesh alternately with the respective pinions 29 and 3| during constantspeed motion of the bed in its respective directions of oscillation, thelength of the rack being such that substantially at the end of theconstant speed motion of the bed in each direction its trailing end willpass beyond and hance out of mesh with that one of the pinions 29 and 3|with which it was last in mesh. While the rack 45 is out of mesh withthe pinions 29 and 3| other mechanism, presently to be described,effects reversal of the bed. When the bed next reaches the point atwhich it is to commence its constant speed motion the leading end of therack 45 comes into mesh with the one of the pinions 29 and 3| which isto mesh with it during such constant speed motion.

The function of the pinions 29 and 3| is to drive the bed duringconstant speed motion. One of those pinions drives the bed in onedirection of oscillation and the other drives it i the oppositedirection of oscillation. When the pinion 29 is in mesh with the rack45, as shown in Figure 1, that pinion drives the bed during constantspeed motion in one direction. After the trailing end of the rack 45 haspassed out of mesh with the pinion 29 the cam 25 shifts the shaft l1axially toward the left, viewing Figure 1, to move the pinion 29laterally out of the path of the rack 45 and the pinion 3| into suchpath. While, this shifting is taking place the bed is being reversed,and when it reaches the stages on the next oscillatory movement when itis ready to. begin its constant speed motion the forward end of the rackenters into mesh with the pinion 3|, which pinion through the rack 45drives the bed. during constant speed motion in that direction. Theshaft ll always turns in the clockwise direction when one looks at itaxially from its left hand end viewing Figure 1 so the pinion 29 drivesthe bed toward the viewer in Figure l or toward the right viewingFigures 5, 6 and '7, while the pinion 3| drives the bed away from theviewer in Figure 1 or toward the left viewing Figures 3, 9 and 10.

The linear speed of the pinions 29 and 3| at the pitch lines thereof isequal to the speed of the bed during constant speed motion. When the bednears the end of its stroke and the rack 45 passes out of mesh with thepinion 29 or 3| which has been driving it the bed is slowed up, stoppedand reversed, and by the time the leading end of the rack 45 comes intomesh with the pinion ,29 or the pinion 3| on the succeeding oscillatorymovement of the bed the speedof the bed will have been brought up toapproximately the speed of its constant speed movement, where uponcontrol of the bed is again taken over by the mechanism which has beendescribed.

The mechanism for reversing the bed at the ends of its stroke will nowbe described. .The shaft [3 rotates in bushings 46 which are disposed inhearings in the frame and two of which bushings extend axially withinthe hubs of pinions 47 and 49 which are rotatable thereon (Figure 1).The hub of the pinion 4'6 is provided with an annular groove 49receiving a projection 59 ofta member 5| bolted to the frame by a bolt52:, whereby to hold the pinion 41 against movement relatively to theframe axially of the shaft ll. Similarly the pinion 49 is held againstmovement relatively to the frame axially of the shaft I! by a plate 33fastened by a screw 54 to the frame and entering an annular groove 55 inthe hub of the pinion 48. i i

The pinion 41 meshes with a segment 59 rotatable upon a bushing 51disposed about the shaft 8, which segment 59 is integral with a seg-.ment 58 of smaller diameter and disposed 013-. posite the segment 59.The pinion 48 meshes with a segment 59 rotatable upon a bushing 39disposed about the shaft 8, which segment 59 has connected therewith byscrews 9| a segment 62 of a diameter equal to thediameter of the segment 58 and facing in the same directionasthe segment 59.

Fastened to the under side of the bed 3 are two relatively shortlongitudinally extending racks 63 and 94. The racks 63, 64 and 45 areall parallel to one another, thejrack 63 being disposed adjacent one endof the rack 45 andovera lapping it slightly (about three teeth) and therack 64 being disposed adjacent the other end of the rack 45 andoverlapping it to about the same extent. The pinion all is adapted tomesh with the rack 53 when the bed is at and adiao'ent one end of itsmovement, and the pinion 48 is adapted to mesh with the rack (it whenthe bed is at and adjacent the other end of its movement. The functionof the pin-ions 41 and 5 8 is to reverse the bed, one of them reversingit each time it 'is at one end of its stroke and the other reversing ateach time it is at the other end of its stroke. As the bed moves in eachdircction and passes the point at which the trailing end of the rack l-5leaves the one of the pinions 29 and ti which has been driving it duringits constant speed movement on that stroke one of the racks E3 and M isinmesh with its corresponding reversing pinion. The reversing pinions'lo'wsto a stop and then turns in the opposite direction, causingreversal of the bed. The re versing pinion controls the bed until one ofthe constant speed pinions 29 or 3! takes charge, at which time thereversing pinion passes out of mesh with the short rack with which itcoop-- erates in effecting reversal of the bed.

To accomplish their functions the pinions 4? and 18 must partake ofangular oscillation. 'The means for imparting such oscillation to thesepinions will now be described. Mounted in the frame is a shaft "85carrying a gear '66 which is always in mesh with the gear so. Integralwith the gear 66 and projecting laterally from a face thereofeccentricallyfthereof is a pin 67. When the gear '66 rotates the pin 61thus partakes of crank motion. Mounted for rectilinear movement in theframe is a slide '68 comprising a crosshe'ad 69 having therein avertical slot it in which the crank pin 67 operates The crank pin 61carries a slide block it which as the gear 66 rotates slides up and downin the slot 70 of the crosshead 6.). "The slide '88 has a guide rod 72which is received by a guide l3 carried by the frame. The slide alsocarries t-Wo racks i l and 1'5, the former racing upwardly and meshingwith the-segment 58 and the latter facing downwardly and meshing withthe segment 62. The slide also has supporting and guiding portions 16for s1idably supporting it on the shaft 8.

As'the-geart'S rotates the crank pin 61 and the slide block "H partakeof crank motion and cause the ciosshe'ad 69 to move back and forth withsimple harmonic motion. Since the rack 14 is always in mesh with thesegment 58 and the "rack T5 is 'alw'ays in mesh with the segment 52,these segments and also the segments 56 and 59 are constantly beingangularly oscillated, and since the latter mentioned segments are alwaysin mesh with the pinions 41 and '48 these pinions likewise constantlypartake of angular oscillation. As indicated above the timing is suchthat each reversing pinion takes control of the bed at the end ofconstant speed movement of the bed in one direction, brings the bed to astop and moves it back in the opposite direction untilitattains'approximatelythe speed of its constant speed movement,whereupon the means for driving the bed in constant speed movement takecontrol.

A complete cycle of movement of the bed is illustrated in Figures 3 to10, inclusive, which show the relation of the parts at various stagesthroughout the cycle.

'The be'd carries plates H which ride upon roller 18 which intu'rnaremounted in tracks"!!! carried by the press frame whereby the bed ismounted for antifrict'ion movement. It is guided in its oscillatorymovement by opposed guides coopcrating with portion of the press frame.

By the mechanism described the operation of the bed is eifected andcontrolled in a remarkably advantageous manner, eliminating entirely theheavy hangers and cooperating parts heretofore customarily employed andwhich have necessitated massive design of the entire press, especiallywhen it is intended for high speed opera.- tion. My bed motion providesfor relatively light design of a press for given duty and given speed,resulting in a very large saving in first cost, cost of operation andcostof replacement parts as well as an important saving in spacerequirements. While I have shown and described a present preferredembodiment of the invention, it is to be distinctly understood that theinvention is not limited thereto but may be otherwise variously embodiedwithin the scope of the following claims.

1. Operating mechanism for a printing press or the like having anoscillating element such as a bed comprising a rack adapted to becarried by the oscillating element, a driving gear continuouslyrotatable in one direction, 'a first pinion continuously in mesh withthe driving gear and also adapted to meshwith the rack to drive theoscillating element in one direction of oscillation, a second pinion,connections between the two pinions independent of the driving gearwhereby tl-ie second is driven from the first but to rotate the oppositedirect-ion and means for relatively moving the pinions and racktransversely "of the rack to bring the second pinion into and the firstpinion out of mesh with the rack to drive the oscillating element in theopposite direc tion of oscillation;

2. Operating mechanism tor a printing press or the like having anoscillating element such as a bed comprising an elongated operatingmember adapted to be carried by the oscillating element, a sh'ait, apair of rotatable members mounted on said shaft, each of said rotatablemembers car rying a bevel gear, a frame mounted on said shaft, the framecarrying a bevel pinion meshing with both of said bevel gears, saidrotatable members and said frame being held against axial movementrelatively to said shaft, means for rotating one of said rotatablemembers, means for moving said shaft axially to shift said rotatablemembers relatively to said elongated operating member to bring saidrotatable members alternately into coacting relationship with saidelongated operating member and means for holding said frame againstrotation whereby said rotatable members will rotate in oppositedirections when one of them is rotated and will respectively coact withsaid elongated operating member to drive the oscillating element in itsrespective directions of oscillation.

3. Operating mechanism for a printing press or the like having anoscillating elementsuc'h as a bed comprising an elongated operatingmember adapted to be carried by the oscillating element, a pair of'rotatab'l'emembers, connections between said rotatable members to causethem when one of them is driven to turn in opposite directions, saidrotatable members being adapted selectively to coact with said elongatedoperating member to drive the oscillating element in its respectivedirections of oscillation, means for shifting said rotatable member'srelatively to said elongated operating member to bring said rotatablemembers alternatively into coacting relationship with said elongatedoperating member and a driving member separate from said connectionsccacting with one of said rotatable members to drive it in all positionsthereof.

4. Operating mechanism for a printing press or the like having anoscillating element such as a bed comprising a rack adapted to becarried by the oscillating element, a pair of pinions, connectionsbetween said pinions to cause them when one of them is driven to turn inopposite directions, said pinions being adapted selectively to mesh withsaid rack to drive the oscillating ele-- ment in its respectivedirections of oscillation, means for shifting; said pinions relativelyto said rack to bring said pinions alternately into mesh with said rackand a driving gear separate from said connections at all times meshingwith one of said pinions to drive it.

5. Operating mechanism for a printing press or the like having anoscillating element such as a bed comprising an elongated operatingmember adapted to be carried by the oscillating ele ment, a shaft,oppositely rotatable members mounted on said shaft and adaptedselectively to coact with said elongated operating member to drive theoscillating element in its respective directions of oscillation,connections between said oppositely rotatable members through which onethereof drives the other thereof, a pair of spaced collars on saidshaft, a lever fulcrumed at a point spaced from said shaft and having aportion disposed between said collars and means for swinging said leverabout its fulcrum to move said shaft to bring said oppositely rotatablemembers alternately into coacting relationship with said elongatedoperating member.

6. In a device of the character described, the combination with a frameof an oscillatable member on the frame, a shaft, means for rotating theshaft in one direction of rotation, a gear on the shaft and connectedtherewith so as to rotate therewith when the shaft rotates, another gearon the shaft rotatable relatively to the shaft, means driven by theshaft for rotating the second mentioned gear in the direction ofrotation opposite that in which the shaft is rotated and shifting meansfor rendering the first mentioned gear and the second mentioned gearalternately operative for displacing said oscillatable member.

7. In a device of the character described, the

combination with a frame of an oscillatable member on the frame, ashaft, means for rotating the shaft in one direction of rotation, a gearon the shaft and connected therewith so as to rotate therewith when theshaft rotates, another gear on the shaft rotatable relatively to theshaft, means including gearing driven by the first mentioned gear forrotating the second mentioned gear in the direction of rotation oppositethat in which the shaft is rotated, means holding both gears againstmovement relatively to the shaft in the axial direction and means forshifting the shaft in the axial direction to render the respective gearsalternately operative for displacing said oscillatable member, the meansfor rotating the shaft being arranged so as to be operative throughoutthe range of axial movement of the shaft.

8. In a device of the character described, the combination with a frameof an oscillatable member on the frame, a shaft, means for rotating theshaft in one direction of rotation, a gear on the shaft and connectedtherewith so as to rotate therewith when the shaft rotates, another gearon the shaft rotatable relatively to the shaft, means driven by theshaft for rotating the second mentioned gear in the direction ofrotation opposite that in which the shaft is rotated, oppositely movingsynchronously timed oscillatable means for operatively displacing theoscillatable member at the ends of its stroke, means on the oscillatablemember for connection with said oscillatable means when both of saidgears are inoperative with respect to the oscillatable member andshifting means for rendering the first mentioned gear and the secondmentioned gear alternately operative for displacing the oscillatablemember intermediate the ends of its stroke.

JOSEPH SINKOVITZ.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 477,200 Crowell June 21, 1892477,738 Crowell June 28, 1892 1,559,962 Heinitz Nov. 3, 1925 1,810,130Collyer June 16, 1931

